I would like my D6 bus without a side of Hitler, please.

Twenty Metro buses are crisscrossing the nation’s capital with Der Führer on their sides for the next month, thanks to an incendiary, anti-Muslim ad campaign by the American Freedom Defense Initiative.

The westbound D6 featured a PNC Bank ad early Monday. Whew. But Shanna Dick is ready for Hitler’s face if it ever appears on that route.

“I just want to draw a big crucifix over his face, so I don’t have to look at it,” said Dick, 44. “Two wrongs don’t make a right. Hell isn’t big enough for him. And the side of a city bus isn’t the right place for that kind of evil, either.”

Adolf Hitler is a little too present these days.

There’s the video parody showing Hitler denouncing the Affordable Care Act, there’s the Hitler goldfish, the Angela Merkel Hitler mustache shadow picture and the ever-present last resort on Capitol Hill when a politician runs out of hyperbole.

Hillary Rodham Clinton, Sens. Marco Rubio (R-Fla.) and John McCain (R-Ariz.) — among many others — have recently compared Vladimir Putin to Hitler for his saber-rattling in Ukraine.

But we’ve also seen Hitler invoked by critics of Wal-Mart, the Common Core education standards, President Obama, former president George W. Bush, union opponents, the American Humanist Association and tax equality.

Let’s be clear: Adolf Hitler orchestrated the deaths of millions of people. A new way to do math is not the Holocaust.

And constant comparisons to Hitler will eventually dull and deaden the association with pure evil. Like yelling fire in the theater, if another Third Reich ever begins rising, we’ll all be too numb to notice.

The ad on the buses says: “Islamic Jew-Hatred: It’s in the Quran.” It shows a photo of Hitler meeting with Haj Amin al-Husseini, a Palestinian nationalist who was an ally of the Third Reich and is described in the ad as “the leader of the Muslim world.”

The ad calls for an end to racism by ending U.S. aid to Islamic countries. And the Washington Metropolitan Area Transit Authority can’t do a thing about it.

The last time Pam Geller, the head of the conservative institute that placed the ads, bought space for another anti-Islam screed in 2012, the transit agency tried to get rid of the ads that called Muslims savages. But the First Amendment — and a federal judge — said too bad. The ads are free speech.

Geller said she has received hundreds of e-mails supporting the bus ads. “The image of Hitler and the Muslim world’s most influential leader demonstrates most vividly the whitewash and scrubbing of history. I used the image precisely because people are unaware of these facts, and because they need to know them,” she said.

Many more ads are planned on buses across the nation.

Debbie Polhemus, a D.C. schoolteacher, covered those ads with hundreds of sticky notes. Oh, Debbie! Can you help us again? Shanna will join you, I’m sure, with her crucifixes.

There is no doubt that insensitive, harsh, graphic and inflammatory ads can do more harm than good. It’s a controversy that pops up every couple of years. In 2012, it was an ad against the Affordable Care Act in the Clarendon Metro station that said “Go to hell Barack.”

In 2009, there were the anti-gay ads fighting same-sex marriage voting. (Oops, that failed.)

Imagine being stuck behind Operation Rescue’s “Truth Truck,” a vehicle plastered with huge photos of bloody, mangled and decapitated fetuses, when you’re stuck in traffic getting your children to soccer practice. Lovely. Thanks for giving my kids nightmares for years, people who claim to want to save children.

And how about a day when you’re stuck behind a “Love Your Butt” colonoscopy ad?

Really, what ends up happening with much of that ad space is that it becomes a paid forum for age-old wars. The Muslims take advertising aim at the Jews, the Jews advertise right back. The atheists buy a bunch of ads at Christmas, the Catholics buy more. It’s pretty lucrative. If cats and dogs had cash, Metro would have enough money to finish the Silver Line on time and begin building a gold one.

But with the First Amendment comes responsibility. And shrill use of our freedom to speak is nothing but abuse, especially when it comes to invoking Hitler. Hitler should be featured prominently in history books and Holocaust museums.

But not on my D6.

To read previous columns, go to washingtonpost.com/dvorak.